COBOL Developper / Brussels

We are seeking an experienced Mainframe Programmer / Technical Analyst to join our technology team. In this role, you will be responsible for the design, development, maintenance, and support of business-critical applications running on IBM z/OS environments. You will combine strong technical programming expertise with analytical problem-solving skills to deliver reliable, scalable, and high-performing mainframe solutions that support key business operations.

Working closely with business stakeholders, analysts, developers, and infrastructure teams, you will play an essential role in maintaining legacy systems while contributing to modernization initiatives.

Key Responsibilities

• Analyze business and technical requirements to design, develop, test, and implement enhancements for mainframe applications.

• Develop, maintain, and troubleshoot applications using COBOL, JCL, VSAM, and other IBM z/OS technologies.

• Support and optimize batch and online processing systems to ensure performance, stability, and operational efficiency.

• Investigate production incidents, perform root cause analysis, and implement sustainable solutions to prevent recurrence.

• Collaborate with business analysts, QA teams, infrastructure, and operations to deliver high-quality solutions throughout the software development lifecycle.

• Prepare and maintain technical documentation, ensuring compliance with development standards and best practices.

• Participate in code reviews and contribute to continuous improvement of development processes and coding standards.

• Manage application deployments, version control, and change management activities.

• Ensure applications comply with security, audit, and regulatory requirements.

• Provide production support, including participation in an on-call rotation when required.

• Contribute to modernization initiatives, including integration with modern platforms and technologies where applicable.

Required Qualifications

• Proven experience developing and supporting enterprise applications in an IBM z/OS mainframe environment.

• Strong hands-on experience with:

  • COBOL

  • JCL

  • TSO/ISPF

  • VSAM

  • IBM utilities (including SORT)

• Experience working with DB2 or other mainframe databases, including embedded SQL.

• Familiarity with enterprise batch scheduling tools such as Control-M, CA7, or equivalent.

• Experience using debugging, diagnostic, and performance tuning tools.

• Strong analytical and troubleshooting skills with the ability to resolve complex technical issues.

• Solid understanding of software development lifecycle methodologies, including Agile and/or Waterfall.

• Excellent communication and stakeholder management skills.

• Professional proficiency in Dutch and English is required; French is considered a strong advantage.

Preferred Qualifications

• Experience developing CICS online applications.

• Knowledge of source code and change management tools such as ChangeMan, Endevor, or similar.

• Exposure to mainframe modernization initiatives, including API enablement, application rehosting, or platform migration.

• Understanding of DevOps practices within a mainframe environment.

• Experience working in highly regulated industries such as financial services, insurance, government, or other large-scale enterprise organizations.

Education

• Bachelor's degree in Computer Science, Information Systems, Software Engineering, or a related discipline, or equivalent professional experience.